The perceptual tasks used by Pollack to examine perceptual development from childhood to early adulthood are being used to determine changes in reception and integration of sensory information throughout adulthood with subjects aged 20 to 79 years. With his tasks used to investigate the Type I process, the effects of receptor aging on perceptual functioning can be determined. Similarly, the tasks associated with the Type II process provide a means by which changes in a higher-level perceptual process, i.e., temporal integration, can be investigated. Several of Pollack's tasks also provide tests of the stimulus persistence model and its underlying mechanisms. In addition, the results of the present research effort can be combined with the data obtained by Pollack over the last 15 years to provide a continuum of data on changes in sensory and perceptual processes over the entire lifespan. BIBLIOGRAPHIC REFERENCE: Amberson, J. I., Atkeson, B. M., and Pollack, R. H. The dark-interval threshold across the life-span. Manuscript submitted for publication, Journal of Gerontology, 1977.